Last summer, my oldest daughter, Sapna, passed a multiple-choice driver's exam, secured a learner's permit and asked to sit in the driver's seat. This was a source of concern for me. As an epidemiologist, it is my job to look at incidence and prevalence of disease in large populations and suggest ways to keep people healthy and safe. I know that motor vehicle crashes are the leading cause of teenage death, accounting for more than a third of the fatalities in this age group.

My wife refused to teach her, fearing for her own and our daughter's life. So I became her driving instructor. I decided to treat this like a business deal and take full advantage of the situation, leveraging my daughter's intense desire to learn this skill with my equally intense desire to impart wisdom to an impervious, iPod-carrying, too-busy-to-talk adolescent.

For a few early Sunday mornings we circled the parking lot of a nearby middle school in our Memphis suburb. I planted imaginary cars in the white-lined parking spaces. If she cut too wide or narrow, I would declare, "Oops, you just swiped a white SUV" or "Oh, my God, you just smashed into a Lexus!"

A few weeks later, I surprised her by asking if she wanted to make her first road trip. Within minutes, she stood with the keys, permit stuffed in the rear pocket of her tight jeans, cellphone in her small purse, next to what we'd jokingly called "her car": my old Avalon.

After a few spurts of accelerations and my hyperbolic, "Oh . . . I just got a whiplash," she turned onto the main road, home to the school where we'd been practicing. As I recall, some years ago on this road, three high school students had died in a car accident. In the past decade, crashes had killed nearly a dozen teenagers in the area. On the same road, non-injury crashes and fender benders were common. Returning home from work, I would often see broken glass and antifreeze leaking like a blood spill at the site of a recent accident.

My initial ground rules for driving instruction included a good attitude, no radio and no passengers other than me.

For the longer run, I followed the example of a friend, who had signed a formal contract with his daughter after she received her full license. He'd downloaded the document from http://www.parentingteendrivers.com.

"It's been the best thing we did," he told me. "It forced us to sit down and talk about all the driving issues with my daughter."

So early this month, my wife and I sat down at the kitchen table, with our daughter seated in the middle. She read the "Driving Agreement" out loud, word for word. My wife and I wanted the 10 p.m. curfew to be in place for six months; my daughter wanted two months; we compromised on four. We made new rules, such as "call when leaving and/or when arriving." In the end she initialed each page, and we all signed the contract.

· Passengers: Studies show that if a 16-year-old driver has passengers, the chance of a fatal collision is more than 4 1/2 times greater than if the driver is alone; if the passengers are two or more teenagers, a fatal crash becomes almost eight times more likely.

· Alcohol: Twenty-three percent of drivers ages 15 to 20 who died in motor vehicle crashes had a blood alcohol level over the legal limit, and one in 10 teen drivers reported having driven in the past month after drinking alcohol.

A study published in the July issue of the journal Accident Analysis and Prevention found that curtailing alcohol consumption among those younger than 21 has led to an 11 percent drop in alcohol-related traffic deaths among youth. Virginia has just toughened the penalties for teens who drink and drive, making it a misdemeanor that carries a mandatory one-year driver's license suspension. I know that such measures work. States with good programs have reduced deaths among 15- to 17-year-old passengers by almost 35 percent, for example.

Driving with my daughter on a long stretch of traffic-free road, I used my newfound dad power to talk with her about college choices, good study habits and avoiding drugs and alcohol. On one of our drives, as her confidence grew and as we passed the middle school again, she revealed to me nonchalantly that she may want to pursue a career in public health and medicine, a passion of mine.

As my daughter slowly gained skills in switching lanes and making smooth stops, I eased up on her restrictions. Initially, I was the sole passenger, and we drove only on Sundays. Then one day I agreed to have her drive with our two other children in the back seat. They sat quietly, motionless, focused on my instructions to her. She had become a responsible near-adult in their eyes. Except for a few wide turns and a yellow-light indecision, her driving was impressive.

After she pulled into driveway, she asked her 8-year-old brother (usually her foe), "So how was my driving?"